INVESTIGADORES
CABELLO Julieta Virginia
congresos y reuniones científicas
Título:
THE LEADER INTRON PRESENT IN THE CYTOCHROME OXIDASE SUBUNIT 5C GENE STRONGLY ENHANCES TRANSLATIONAL ACTIVITY OF THE SUNFLOWER HAHB-4 PROMOTER
Autor/es:
CABELLO, JULIETA V. AND CHAN, RAQUEL L.
Lugar:
Pinamar, Buenos Aires
Reunión:
Congreso; Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB); 2005
Resumen:
Arabidopsis thaliana cytochrome oxidase subunit 5c is encoded by three genes that present a leader intron in a conserved position upstream the first ATG.  It has been reported that removal of this DNA segment produces a strong decrease in the expression of a reporter gene in transgenic plants. Hahb-4, a member of the HD-Zip I family of transcription factors, is regulated at the transcriptional level by drought and ABA. Constitutive expression of this protein confers to transgenic plants a strong tolerance to water stress, associated to a slight delay in development. Arabidopsis thaliana plants transformed with Hahb-4 whole gene present water stress tolerance but no so high as plants bearing the 35S CaMV promoter. In order to optimize drought tolerance and avoid negative phenotypic characteristics, we have introduced the COX5c leader intron into the Hahb-4 promoter region and transformed plants with this construction. Histochemical analysis show additional tissue/organ expression and fluorometric measurements indicate a of 5-6 fold increase in GUS activity. The results indicate that this heterologous chimeric construction is well recognized in Arabidopsis, presenting a high reporter gene activity and constitutes a new biotechnological tool for transgenic expression of this, and other genes in plants.